SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d3a236d355b6b913e961a58b38eb7f0708480f2e74e8c30f1229fdd6763e95a' 
  AND token = 'VvQle+QcOzbNRLcLJH32Whx6VQljXt78spjl03+moHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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