SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed4d959727b411ab0b186186a7458a254ffd936e80cca4511d60b012b1aa64e1' 
  AND token = 'k2+IzjAowuUuyu10GfjMTGdpHxSjTYMOCwZ2pESkUH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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