SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23544c758edc12a9a931953df81f81dab9de06f3257a69a2fb75dca84413fa8c' 
  AND token = 'wTlkgcq7QusLH1tEaVETC/EisTxLOgUZJp2Q4Hq7F64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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