SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd280bcb14d700dc28890dc58555eedd270a7701b4be648d0fdf383a431012519' 
  AND token = 'u72TnBayigHJDxhmNyJuzaa850ZV12YI2iMwG2Psavs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}