SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe0026210dfe2e43595274e22555c1f83e1de71aad9c9693289e0b4a1c2e6d5a' 
  AND token = 'o8JE5yvS4sIgi0jlCWuArfULPosOhiEKkAm73ExWwEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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