SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8ee634a8e642c6c375fce3c2e2f766110609392948b57c00fb8934274677cf3' 
  AND token = 'pX0NTEfHtCYIz1ziaZcK2L732xiDSxQGkb0vfzY1PaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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