SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfc89ab6229fc6aa4a360ae955497579193d723f623515ba2e7be9f638edef1e' 
  AND token = 'YZbAXpqq6t+FpWj/zQXP9Q/DBGB6i0bpsEcHiDv3vc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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