SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb94a6a1739c97f815b7875c50f76e874a9e2b285b0a40e65e7d8eb68fbcb3b2' 
  AND token = '+VigpW/Ng2lsYiYXcrpIzLL6PIJkWr4RGuz4AvIM6yE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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