SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cd0ddd4eae7f0fa3d03003ea43c03ff467f3e3ae9a144c058c0e1a4b14f41ab' 
  AND token = 'MxWMueM0atmzzro54Kve/IKIv+jnTUpDSFdr3vn93Qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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