SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2688a2e6119353762e912bf605e053a258d7d9858bcebafe08b63d545cfec6e' 
  AND token = 'Oz5o95mXoRgAV5noYZsE94sRZ282aukRp9gFbvbHOxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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