SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '252f8c0993e12ca3a1e48842cd97deb37a519287a045529252c186c62ebd43a5' 
  AND token = 'J2I9S0mR1FOFQQ/d/gc9HrN8f/7vVHwB+GiFHotng3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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