SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7037420f4a6d5502bf35af01d64b44c044f9e81b0cdeb3f936932b5a9300b13' 
  AND token = 'F3zJccG0RskFgz/MHHTg6ZInXTrzd0ITUSqgO9tOve0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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