SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7f4215015ed9fc7018628e11374904befb5cedf1c0f24f0ede92f2e60be969d' 
  AND token = 'jqUBTCpoZp6XGxOCsnGuchZX9R8dHchqhFHkjUGLjXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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