SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '848224b39afe995de0ce2ded62895b09006a58723352a33187816340d689c84b' 
  AND token = 'Nlo+fd3ibf87VGMDSB2rLoYZz8wgJgKnd9pgTQhWqzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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