SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25eb0608770bbf94f115a27132182341904e24c4f3f368536d13a31199af9559' 
  AND token = 'rRXa2fqtEA0XE1TDiNC0OZenNo49pBiRsfw+rMaUwVo=' 
  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"
    }
  }
}