SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b045f4b7fb3b623d0ae486b3dca0170b9b6a4efcd62e807766aacfdbfbfd0ad2' 
  AND token = 'U33C49157UyvUE93RrIelrlo1SFcEQFKm63+gITFYC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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