SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad733837b02bb4fc602d59fdff49fd166dab841feda67995a034950c1f8ff62a' 
  AND token = 'pWXf3Jf9AvuBvFQJiDLCGKpP3szLtKts+4f2qg1smbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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