SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ebcde3e02dd74328704c694f64507dbb3699c1c2207dee8e033d933e6c743d1' 
  AND token = 'qdt9tGLMkWNnYCmxsBdF73yrvwraPiLIO+y7wo95EtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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