SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6c68898eea19b749e41ebef494620edb5273db42d0c978a2340150c00fcdee5' 
  AND token = 'uvdvII+3T/JHzKN+BlqvpHr6S5w4tbhSupilx2G5Z0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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