SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7310cc2a1a87443646e221d2125d577015b00318cf60f78c1786106f69f29851' 
  AND token = 'YdUpgGsUPlEUJkiaN5pYCJVfBZ7W1go5o5hmnmXfFjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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