SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f20cc32789f5993cc4c04a95559c42f8b2578a81f257a3b5a3bd86be35ff5384' 
  AND token = 'vnD6NUVi2V/CPaRmKBGF8M9kQ6s2mhPd1kdIjAmYSLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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