SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '547d3fa909882122c4fe31ddd617e88aef29f5dd8ba42bc58bd17b1c0770c301' 
  AND token = 'K9CgBqa2ZzHSD0RVeGJzvokrIojcBRc2Tvvb/qx+fEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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