SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e447f611bf5f3847cd400248f52239259e8f7a7d69e0ca1fddd515a566169638' 
  AND token = 'dfARmAnZRlvZqWwYQ1mnVp5Ck3XPRkt4pkH9VdDUvXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}