SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30e4b033656f092a062342ec06796565ef4910e70132b372321a7f6cba638de2' 
  AND token = 'DvQPpr5wGXsCT+i8CvgI9s+ABWH3W4Xbzk2e6UUzp1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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