SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '079e715bd1a46dec5b5314328740a129ce223b75e7288fabb0cd18aac39eb7ba' 
  AND token = 'zd6WZNb+cCPj0bfNwsPMSDPLzimq69whmaSQidWdKS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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