SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cb9a089b4f82702bbc26a698666c90b58cc5ced699f70f672b3db04472746e1f' 
  AND token = 'S/yvieX0/REnwsR1VJCNRIcnQJYzOTaI/2OaM+yDWBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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