SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0986d1db4d34342fa4ad92092d6bc9d957ed35ee4ba23e02840e53dea6e204a9' 
  AND token = 'tkhOlfBPdeEp9ZParrvlORhDa5ZshlYVPKDNGLtyEbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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