SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fb1313950e1ea9542a64cba24ceea82eef6ef3a3826565cfd81a0b529c2793f' 
  AND token = 'M6GgcfS0DarFLPaX4Iw++km5bOH1eb4d3zFPh4lFNlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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