SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb8a568db4bc26851c659781fdff30c059f95185881677995810216473a8635e' 
  AND token = '+StPFfit/0MZ5BdITXGnwD7SKWssh+qPGuTufcRRkNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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