SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fcb13b83d4783fc4744403c25ed1ac336f02ec59723a26198f4393255e63bfe' 
  AND token = 'ucCAbIQedVV/f2+TEvrX4EMotBUXMtaGgEbtlYuyFD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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