SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ce6b7e724ed27f10dc62c432901bd28a9ee4792989766488f8816afe50b11e3' 
  AND token = 'Uq/TUyGabcoSllnwGg4tv1ZbR/MOZs5QtldTdhuEXgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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