SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be4715022588672c7523e6ed50ac3d1361abd27adbab770e913ed6876f97aeb7' 
  AND token = 'hzgt0YZw9vaRMGOL8GhfqSWRuR2mk5CI3yWMykhBo0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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