SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba66c8bc4aa0e36d6d82aa1cf44cf41c2d428c0146983ad9af8e8a78d64a79b0' 
  AND token = 'mnVS8QlNRTVecUHN8AxTyjUGuCOhqEmIkJYBga6T2kY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00097

JSON explain

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