SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bbd527813a1ff0c595b43d51d63d88850a1a7c7b196ae075ad2d9d0a81280de5' 
  AND token = 'xFANuQN7HP2fSoGtmt3XQLCkq2WexOhGUHDnzMPsTCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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