SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77c28de3534137983dd6025253ff4395f2c3f48a315981c15d753e8a3ee6f8fa' 
  AND token = 'TniRGyYGQkfF0zVOSIrH5zSx+N+Lhgy6o9Ennt6YKCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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