SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '882b46d1e19cffae7b2dfa3ae8bf81550023f7a0d864325f436c9eca039f5b7c' 
  AND token = 'l6kSZkxNUpYR9j1ZFPD+W1Q/DQpfuYEqyjQXYEXoUnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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