SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bdc9afff153d4206ee38a47bc78b47ef5816c0c25c8e0ef04fcd74b354c55fb' 
  AND token = '78/8Hxc9PeakLuA3FDdDRO6NtZswByTJJYjq6tOdXGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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