SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e35adb5ddfec5ecdfce09e0d593a688b1836ff9a26bb14597b205f7a5736888c' 
  AND token = 'K10qU4YcoALCz6kQGyGXjO9UBl+M8Gq+8X/FBL4K4Ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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