SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bdc2f62ea8a7c80949d8cdcea15dc57143ba00d535b2348a56956a6e269eb181' 
  AND token = 'eutHV5cShIsPO7LIScfprkKsf+TaDt0leoslfRrVfj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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