SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a080cbf4c47bfba97f15e22afcb5cf9127d60b8ed6e1c40bdf3618c5733278e4' 
  AND token = 'qbnBQl+su1KOZ/JIKlCtZ51UPydM3sJTbsL4WYjNsWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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