SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0db138ee804e7fb03fffa7ab3ea9aa4ebc75c23189b743b699809632725a242c' 
  AND token = 'Jp4NLJtTlQMn2ZW5RPoBl43n2TsXtmwWpQI2Rjf9grw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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