SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a6d55931f6dc4fe898326831fee85c4cc38fd2fb4c007cc78f1172a1345c0055' 
  AND token = 'YPn+UF/VJxFcSOlNfZCN8WViF9VQqKi9P4lZYUEF47M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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