SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eac70b0cde49b2cbfa79ea5bc5552f76cc210f23b051163764869221fed23dc1' 
  AND token = 'mLVvlwZOsVy0K+kD7OpUOuDEbPfdmhGlgLsI3K0xg4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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