SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8d6e795cc9fba352bd488ce7145c883ed3aeb1ddc676d969396ee42e4af85ae' 
  AND token = '4bA9VZb+z6Y0TBHilbQdptTLdr5uEgKIu+J+8si4dKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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