SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f0f847c3f3fb0346319824d58ec56e191c07b31d6a1cb664a1231e50c982c30' 
  AND token = 'TeD+VBBBaOlhwxQvVv2wPCW/3y46v1mzw1KglJPUzYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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