SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '003d075714557006ccda252423fc2aa486ab72becf645b0db4f0bd74a61a3617' 
  AND token = 'xTUpj95A2y6nlRH2dvF2V5j8OaKGTWri/wlzwx+HUsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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