SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '984fa1c375d04127f75d2a51dd3fc0fed3fb31276f3fe0357115cc70b4acc0aa' 
  AND token = 'ZCVDdwoJqOQaMni7q5/KiEwrmWB1YIUy+k3BaDLSsrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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