SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5f60d3e82dc1773d775516bdce9892710d3da52438e0de604f75cba6b31b381' 
  AND token = 'mAXDHb5JBN02HsM/JIL15Mcdg8BanlLOg+YvptHRLYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}