SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '901fc21f5944811d8cf82262cefece5cb5de29583029d959ad786e13a24f3a86' 
  AND token = 'RgiyJH8+dDFW8e+V5xckG1qbOpJMT72FJyUJW7EZ00E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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