SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd2aa5255337532075e759fd779b1f4745a1e3eb02659f39465505de4cf53fcea' 
  AND token = '6AfErcasEFlTiRtqP6eUtQKf4pfxPDso57MtP4JiPRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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