SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '173a4092bb7a5d3457387951cb09ef38e396442604aee92289001e7a0673b59a' 
  AND token = 'AFEQAcEba26eLrklEn3yMhmlz66S9ZlsDYP3M1stPmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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