SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecdbedd626fa4388b82b315dee6320ca1cd23fdfd1bbc5c6b82a25a56849dab9' 
  AND token = 'LZxw6fe32b3QmWhsRiJO4kEafQZjFoLANWC5LPiKQoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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