SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0df515e9bbb89e10dec648b118dd0f340935bb045e0e5dba298ca212bb74c295' 
  AND token = 'x8zez1IriEWAMw/fpWASUK/rgTc9jEoJSPD04SNfw0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}