SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b7393b6ce79ad0dbf86ee246bbe3544ea7936811f132660b408bf478b942c89' 
  AND token = 'HZHsuQaO8ZD4jSpSfQR1DvpcbyMxL3TRbmdezLzo2Pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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