SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc719f25206ba042a3d5bcbcd8a901a128451fdc9eeda563ec3a01c2f6299e04' 
  AND token = 'yshNqgXK9oBZZAZgXR0sQWr0PK+z1Vwhl51qZb9eW+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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