SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63f16575e84ffdbcc519dd7a83d1144bb3f7119bffe9b9813734bd03fa22a0cc' 
  AND token = 'OGIWIiVGTLBFZ+F7P0mBDU66LrvLfgLmh8+lsJbNR6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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