SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ffa78d6bd4a88302d2ac89b3abeed9ef7d4afc4d3f41b6bea1b95a6abd1b232' 
  AND token = 'WgnkiSSwEtEjPtP4CcPtmBdfjcOjH2YloVHNP4T+mjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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