SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5ba6d6dc747cec06e57db26d052815df542a63aa076373b3e16d66b1d439c9f' 
  AND token = 'S+iMQKpwHYPqGy9V8+2T31UgvM5Io7hglznUA1DuYe0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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