SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4307373e480d9a01633712b1f7eba222d7084f9d9166315b8f87681366f1985f' 
  AND token = 'Nd0rxEblvSm8KHesxtpF78uTJgePYl/cj7cfsrmJDRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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