SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3013caf9d1553cd33a56f0127f46bd8c18338146edfd81cfd3498a314c606bfb' 
  AND token = 'v7mgtWkoInbTpugQNeR4nReXMqYM+JvH0cBKYye1iCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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