SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0b1885f5ffb48e4646ed1da388951b8c873c884dc547d2a1dc289c437214b53' 
  AND token = '3WJYH4MXidzGuiLigTjctnhCG9eF2r4vGxEWfjN17So=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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