SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '56cda69c28ce9833cdfef19acd70d881fd4e2b2e45e993d36e1854dd4186e4d6' 
  AND token = 'ztCmAwFzsAcksuIzlROjCfOYd+zghhgcrb5BTQkwPuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}