SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff5f9ceb1059060b36e5ccf572d54d31368e70a227e7e37754ca69affa02207a' 
  AND token = 'Q/1+mQjZuwKbVzv92RdTyXpmgLlABHeELkLCgjKx1Ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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