SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d07ebd8247422938f9bd651603ee59b88d6ee6af71e156ac3121414f30698d' 
  AND token = 'dYAAN37kTLVT05/Cx41z0Ku8kjrqFoR2ZN6AW4KtB1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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