SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4cea3745f2332542b38afc7b3aa515d7c2ded314db53ff420c60fd8d1a80897' 
  AND token = 'Tud2D9FNGYTxhJhRwlQqQRMo8QXugIVz13aM0kHsTKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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