SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bea8fbd3d529f31861281f4ec5222085b85102ed2e24dadd769f7cde682d8e0e' 
  AND token = 'PS6rpujfnaN2LlUMp/xnCkkCVmzfUWfsaD53txrFvFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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