SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eed852f5b4c0859e274ebb325ba75afc65081ca91d955c5db5b71032e3298526' 
  AND token = 'S4V1I8S6HemJgSiqcIcDxnRL/i1p4MDe6eSKaLHmVuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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